2,4,5-trichlorophenylazo-2-phenylindole



United States Patent 3,526,619 2,4,5-TRICHLOROPHENYLAZO-2-PHENYLHNDOLE Heinz Haubrich, Leverkusen, Germany, assignor to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Aug. 31, 1967, Ser. No. 664,650 Int. Cl. C0911 29/36; D06p 1/02, 3/04 U.S. Cl. 260-165 1 Claim ABSTRACT OF THE DISCLOSURE An azo dyestulf especially useful for dyeing and printing of hydrophobic textiles or fibers, the dyestuff having the formula and a process for its preparation by coupling diazotized 2,4,5-trich1oroaniline with Z-phenylindole.

1 ams-C and is eminently suitable for the dyeing and printing of materials, e.g., fibres and textiles made of hydrophobic materials, especially of textiles or fibres made of aromatic polyesters, for example polyethyleneterephthalates and ICC synthetic superpolyamides. Dyeings obtained on such materials are characterized by very good fastness to light and washing.

The parts given below are parts by weight.

EXAMPLE A solution of 196.5 parts of 2,4,5-trichloroaniline in 1000 parts of sulfuric acid monohydrate is slowly diazotized by addition of 69 parts of sodium nitrite. After stirring for half an hour the solution is poured onto ice and a solution of 194 parts of 2-phenylindole in 450 parts of sulfuric acid is added. The pH value of the resulting solution is adjusted to 1.8-2 by the addition of an aqueous solution of sodium hydroxide or sodium acetate. After completion of the reaction the resulting dyestuff separates in the form of dark crystals which are suction filtered, Washed until neutral and dried at -60 C.

25 parts of synthetic superpolyamide fibres are introduced at 50 C. into a bath of 4 litres containing 4 parts of an emulsifying polyglycol ether, 0.4 parts of the well dispersed dyestuif and 10 parts of a carrier, for example benzoic acid and 20 parts of diammonium phosphate. The bath is brought to the boil within 30 minutes and dyeing is continued at the same temperature for 1 /22 hours. The dyeing is subsequently washed alkaline at 70 C. for 20 minutes, rinsed and dried. A clear yellow dyeing is obtained which is fast to light and washing.

What is claimed is:

1. The monoazo dyestulf of the formula l C 5115- C i References Cited UNITED STATES PATENTS 1,835,393 12/1931 Hentrich et a1 26016S 2,970,994 2/ 1961 Kruckenberg 260- 3,255,173 6/1966 Dehnert et al. 260-165 XR 3,347,844 10/1967 Rhyner et a1 260-465 FLOYD D. HIGEL, Primary Examiner U.S. Cl. X.R. 

